*Article* **Combined Processing of Micro Cutters Using a Beam of Fast Argon Atoms in Plasma**

**Alexander Metel \*, Yury Melnik, Enver Mustafaev, Ilya Minin and Petr Pivkin**

Department of High-Efficiency Processing Technology, Moscow State University of Technology STANKIN, Vadkovskiy per. 3A, 127055 Moscow, Russia; yu.melnik@stankin.ru (Y.M.); e.mustafaev@stankin.ru (E.M.); i.minin@stankin.ru (I.M.); p.pivkin@stankin.ru (P.P.)

**\*** Correspondence: a.metel@stankin.ru; Tel.: +7-903-246-43-22

**Abstract:** We present a new method for coating deposition on micro cutters without an increase in their cutting edges radii caused by the deposition. For this purpose, the cutting edges are sharpened before the coating deposition with a concentrated beam of fast argon atoms. The sharpening decreases the initial radius and, hence, limits its value after the coating deposition. The concentrated beam of fast argon atoms is generated using an immersed in the gas discharge plasma concave grid under a negative high voltage. Ions accelerated from the plasma by the grid pass through the grid holes and are concentrated in the focal point of the grid. As a result of the charge exchange in the space charge sheaths of the grid, they are transformed into fast atoms. A uniform sputtering by the fast atoms of the micro-cutter surface reduces the radius of its cutting edge.

**Keywords:** micro cutters; cutting edges; wear-resistance; coating deposition; adhesion; plasma; ions; charge exchange collisions; fast gas atoms; etching; sharpening
